The use of dietary supplements is a popular form of health behavior, especially among women. Little research has been conducted to determine consumers' comprehension of supplement label information. Therefore, this research evaluated comprehension of supplement label information among women 25-45 years of age who consumed a dietary supplement > or =4 times per week. Participants (n=51) completed a written questionnaire about supplement practices, a 10-item knowledge test, and an individual interview about terms used on supplement labels. Participants answered 70% of the questions correctly on the knowledge test indicating adequate knowledge of dietary sources of nutrients. Knowledge of recommended dosages, dosing instructions, and instructions about inappropriate use of supplements for certain people also was adequate. However, misconceptions regarding the term "natural" on supplement labels, product claims, and testing for product safety existed among participants. Supplement users need additional education about supplement claims and testing for product safety and efficacy to make informed health care choices.